Snow handling apparatus

ABSTRACT

Snow handling apparatus especially useful for the grooming of ski slopes or roads or trails used by over-the-snow vehicles. A pan assembly with a flat rectangular bottom panel and opposed vertical side walls is mounted in a snow roller frame to be towed behind a towing vehicle. The pan assembly is pivotally supported at its rearward end on the snow roller axis and its forward end can be raised or lowered relative to the roller frame by hydraulic motors controlled from the towing vehicle. A bulldozerlike blade extends transversely between the opposed side walls and is supported on the bottom panel for movement between the front and rear edges of the bottom panel, movement of the blade again being controlled by hydraulic motors. A gate is pivotally mounted on the side walls for movement between a closed position in which the gate rests on the front edge of the bottom panel and closes the space between the forward ends of the side walls and an open position in which the gate projects upwardly from the rearward ends of the side walls. When the blade is in its rearward most position, the gate when in its open position provides a vertical extension of the blade. With the gate opened and the blade in its rearwardmost position, the pan assembly is lowered to scoop up snow as it is towed. When the pan is filled the gate, which is curved concentrically about its pivotal axis, is closed and the pan assembly is elevated to enable the snow in the pan assembly to be transported to a dumping area. At the dumping area, the gate is opened and the blade is advanced forwardly at a rate related to the speed at which the assembly is being towed to discharge snow from the pan assembly in a layer of selected thickness. The discharged snow is leveled and compacted by the trailing snow roller.

United States Patent 1 Maxey [11] 3,783,949 [451 Jan. 8, 1974 SNOW HANDLING APPARATUS Loren R. Maxey, 615 S. Loomis, Fort Collins, Colo. 80521 [22] Filed: Apr. 5, 1971 [21] Appl. No.: 130,892

[76] Inventor:

37/ll7.5, 122, 123-124, 126, 128, DIG. 2, 5, 9, 129, DIG. 4; 94/50; 214/146 E [56] References Cited UNITED STATES PATENTS 2,025,285 12/1935 Hunter et al 37/129 2,215,026 9/1940 Austin 37/D1G. 4 2,284,412 5/1942 Frentzel, Jr. et a1... 37/DIG. 4 2,419,262 4/1947 Gurries et al. 37/DIG. 4 2,852,869 9/1958 Beyerstedt 37/l17.5 3,313,050 4/1967 Junck et a1. 37/129 3,346,974 10/1967 Haynes 37/ll7.5 3,316,822 5/1967 Seaman 37/ll7.5 2,650,440 9/1953 Quartullo.... 37/126 R 3,152,410 10/1964 Monk 37/124 G 946,978 l/1910 McConnell 172/170 955,590 4/1910 Grimes 37/10 2,227,433 1/1941 Berner 37/126 AA 2,912,826 11/1959 Tan 37/126 A 2,994,976 8/1961 Hancock 37/126 AE 2,786,283 3/1957 Bradley 37/10 3,260,179 7/1966 Moreira 94/50 PR 3,623,406 11/1971 Leben 94/50 R Primary Examiner-Robert E. Pulfrey Assistant ExaminerEugene l-l. Eickholt Attorney-Drake, Crandell & Batchelder [57] ABSTRACT Snow handling apparatus especially useful for the grooming of ski slopes or roads or trails used by overthe-snow vehicles. A pan assembly with a flat rectangular bottom panel and opposed vertical side walls is mounted in a snow roller frame to be towed behind a towing vehicle. The pan assembly is pivotally supported at its rearward end on the snow roller axis and its forward end can be raised or lowered relative to the roller frame by hydraulic motors controlled from the towing vehicle. A bulldozer-like blade extends transversely between the opposed side walls and is supported on the bottom panel for movement between the front and rear edges of the bottom panel, movement of the blade again being controlled by hydraulic motors. A gate is pivotally mounted on the side walls for movement between a closed position in which the gate rests on the front edge of the bottom panel and closes the space between the forward ends of the side walls and an open position in which the gate projects upwardly from gr arwerdfit slspftheater: als

films in its rearward most position, the

gate when in its open position provides a vertical extension of the blade. With the gate opened and the blade in its rearwardmost position, the pan assembly is lowered to scoop up snow as it is towed. When the pan is filled the gate, which is curved concentrically about its pivotal axis, is closed and the pan assembly is elevated to enable the snow in the pan assembly to be transported to a dumping area. At the dumping area, the gate is opened and the blade is advanced forwardly at a rate related to the speed at which the assembly is being towed to discharge snow from the pan assembly in a layer of selected thickness. The discharged snow is leveled and compacted by the trailing snow roller.

9 Claims, 10 Drawing Figures PATENTEU JAN SHEEI 1 0F 5 INVENTOI? LOREIVAMAXE'Y B) @M, MUM @JZMM ATTORNEYS PATENTED 81974 3.783.949

SHEEI 2 0F 5 laaw I INVENTOR 1 LORE/V aMAxEY JM, WM 0% AT TOR/VEYS PATENTED 3, 783 949 sum 3 OF 5 INVENTOR LOREN R. MAXEY CQ/MIAL, ATTORNEYS PATENTED JAN 8 974 SHEET 0F 5 ATTORNEYS l snow HANDLING APPARATUS BACKGROUND OF THE INVENTION The increasing popularity of recreational skiing in recent years has resulted in increasing demand on ski area operators to cater to the desires of large groups of skiers of varying ability. The skier of average ability strongly prefers to ski on a slope where the snow-surface is uniform, reasonably smooth and of a consistency generally referred to as packed powder. In addition to the variations in snow conditions produced by the weather, the heavy usage, particularly on the more popular slopes favored by skiers of average ability makes the desired snow conditions very difficult to maintain, even during periods of ideal weather. Accordingly, ski area operators in recent years have been giving increasing attention to the maintenance or grooming of snow to maintain the 'ski conditions as close to the desired conditions as possible.

In general, these grooming operations fall into one of three major categories. First, after a heavy snow fall, the operator wants to pack or compact the freshly fallen snow on those slopes normally used by the beginning or intermediate skier, because these skiers encounter great difficulty in skiing in loose snow of any substantial depth. Second, under normal usage mounds of snow, generally referred to as moguls tend to build up on the slope in an irregular manner and it is desired to smooth or minimize these for two reasons. The first reason is that many skiers encounter great difficulty in skiing over the bumpy surface, while the second is that the bumps or moguls tend to channel the more experience skiers into confined paths through the bumps, re sulting in heavy wear and scraping away of the snow surface in localized regions, this latter action tending to further build up the size of the mounds. Third, due to heavy traffic or high amountsof exposure to the sun, localized areas of the slope tend to become scraped to the point where the ground or projecting rocks or stumps become exposed. In this latter case, it is desired to transport snow to the exposed area to build up the snow cover.

While certain equipment is available for performing the operations described above, most of the equipment presently available is of a rather specialized nature specifically designed to perform only one of the foregoing operations.

The present invention is especially designed to provide a towable apparatus of general utility capable of performing all of the various operations described above.

Other objects and features of the invention will become apparent by reference to the following specification andto the drawings.

IN THE DRAWINGS FIG. 1 is a side elevational view of a snow handling apparatus embodying the present invention with portions of the hitch structure which couples the apparatus to a towing vehicle omitted, showing the gate in its closed position and the pusher blade in its retracted position;

FIG. 2 is a side elevation view of the pan assembly of the apparatus of FIG. I, showing the gate in its opened position and the pusher blade at its forward limit of movement;

FIG. 3 is a top plan view of the apparatus of FIG. I, with certain parts broken away and a portion of the towing hitch omitted;

FIG. 4 is a front elevational view of the apparatus of FIG. 1, with the hitch structure omitted and certain parts broken away;

FIG. 5 is a side elevational view of the hitch structure showing the rearward portion of a towing vehicle in broken line;

FIG. 6 is a perspective view of the pusher blade assembly, including its driving linkage;

FIG. 7 is a perspective view of the gate;

FIG. 8 is a top plan view of the hitch coupling receiving assembly mounted on the towing vehicle;

FIG. 9 is a bottom elevational view of the coupling of FIG. 8; and

FIG. 10 is a schematic diagram of the hydraulic con trol system of the apparatus The apparatus of the present invention is designed, in effect, as a trailer which in use is towed by a track laying over the snow vehicle, such as the Tucker SNO- CAT. Referring first to FIGS. II and 2, the apparatus includes a main frame assembly designated generally 20 having a hitch structure designated generally 22 and only partially shown in FIG. 1 fixedly secured to its forward end. Referring briefly to the plan view of FIG. 3, it is seen that main frame assembly 20 consistsof a pair of spaced parallel frame members 24 rigidly interconnected at their forward ends by hitch assembly 22 to the rearward ends of main frame members 24 are coupled to each other by a rigid transversely extending shaft 26; which is fixedly secured to the rearward ends of frame members 24- and rotatably'supports a snow compacting roller 28 which extends substantially the entire distance between the main frame members 24. Roller 28 is freely rotatable upon shaft 26 and supports the rearward end of the apparatus, the forward end being supported upon the towing vehicle (partially indicated in FIG. 5) by hitch assembly 22.

A pan assembly designated generally 30, and shown per se in side elevation in FIG. 2, is pivotally supported upon shaft 26 at its rearward end as by bearing assemblies 32 and is supported from main frame assembly 20 at its forward end by a pair of hydraulic motors 34 interconnected between pivot assemblies 36 on main frame 20 and pivot assemblies 38 on pan assembly 30.

Pan assembly 30 is built up from lengths of structural steel welded together into a generally open framework. Referring particularly to FIG. 2, the assembly includes right and left hand side frame subassemblies which include structural members 40, 42, 44, 46, 48, 50 and 52 rigidly interconnected to each other as by welding.

Transversely extending cross frame members 54, 56 and 58 interconnect the two side'frame subassemblies. Cross frame member 54 is preferably formed from a relatively heavy angle iron section and extends transversely of the pan assembly adjacent the juncture of side frame elements 40 and 42. Cross frame member 56 preferably takes the form of a relatively sturdy cylindrical rod or pipe section and extends transversely of the pan assembly from a location approximately above the intersection of side frame elements 48 and 42. Cross frame member 58 likewise is of a relatively heavy angle iron section and extends transversely across the frame at the intersection of side frame elements 52 and 50. It will be recalled that the pan assembly is pivotally supported upon shaft 26 of main frame 20 by bearing assemblies 32, and these bearing assemblies are axially positioned between the main frame and the opposite ends of roller 28.

The two side frame assemblies are likewise interconnected by a bottom panel 60 which is of rectangular configuration and welded along opposite edges to structural elements 46 of the side frame assemblies from the forward end of element 46 as viewed in FIG. 2 to the rearward edge of bottom panel 60 which is located approximately in alignment with the rearward sides of structural elements 48 of the side frame assemblies. A hardened steel member 62 is welded to and extends acoss the front edge of bottom panel 60 to provide a knife edge at the forward end of panel 60 and to stiffen this particular edge of the panel vertical side panels 64 are welded to each of the side frame assemblies to extend upwardly from bottom panel 60 to approximately the upper end of structural element 48 and to extend along the side of the side of the pan assembly between structural elements 40 and 48.

In addition tov the fixed structural frame work described above, pan assembly further includes a gate mechanism designated generally 66 and a pusher blade mechanism designated generally at 68.

Gate mechanism 66 includes a gate member designated generally 70 which is shown per se in FIG. 7. Gate member 70 is constructed primarily of sheet metal and includes a main or gate panel 72 conformed to a cylindrical surface and welded along each of two opposed side edges to side panels '74. Two or more stiffening panels 76 are welded to the interside of main panel 72 as best seen in FIG. 7. On the outer side of each of side panels 74, a crank arm 78 is welded at one end to a spacer block 80 which in turn is welded to the outer side of panel 74 to support crank arm 78 in a cantilevered position in spaced parallel relationship from the outer side of panel 74. Aligned bores 82 and 84 respectively located in the crank arm and side panel are provided to receive a pivot pin 86 which is fixedly mounted within and projects outwardly from opposite sides of the pan side panels 64. When gate element 70 is mounted upon pan assembly 30, crank arm 70 lies at the outer side of the pan side panel 64 while the side member 74 of gate element 70 is located at the inner side of pan side panel 64.

A pivot pin 88 fixedly secured to crank arm 78 projects outwardly from the crank arm to pivotally interconnect crank arm 78 to the piston rod 90 of a hydraulic motor 92 whose cylinder is pivotally supported upon the pan side frame element 42 as at 94. From a comparison of FIGS. 1 and 2, it is seen that when the piston rod 90 of the two motors 92 (one at each side of the pan assembly) are extended, gate element 70 is located in what is termed a closed position, shown in FIG. 1, in which the curved main panel 72 of the gate rests upon the forward edge of bottom panel 60, the main panel 72 of the gate when in this position extend ing transversely across and closing the open forward end of the pan assembly. In FIG. 2, the gate assembly is shown in its open position in which the gate main panel 70 curves upwardly and forwardly from approximately the upper rear corners of side panel 64. To locate the gate in this position, a notch 96, best seen in FIG. 1, is cut into side panel 64 to partially receive the spacer block 80 at the distal end of crank arm 78.

It should be noted that the radius of curvature of main panel 72 is such that the curved surface of panel 72 is concentric with the axis of pivotal movement of the gate assembly established by pivot pins 86.

Structural details of pusher blade assembly 68 are best seen in FIG. 6. The assembly includes a blade 98 having a plurality of stiffening webs 100 welded to its rearward side to rigidify the blade and hold it in the curved configuration illustrated. A pair of rollers 102 rotatably mounted on the outer side of the two outer most webs 100 are supported upon bottom panel 60 of the pan assembly to provide rolling support of blade 98 between its retracted position shown in FIG. 1 and its forward most position shown in FIG. 2. A pair of angle irons 104 are mounted respectively on the inner sides of each of the pan assembly side panels 64 to closely overlie rollers 102 so that the rollers are confined within a channel whose bottom wall is defined by bottom panel 60 and whose upper wall is defined by angle member 104.

A pair of mounting brackets 106 welded to the rearward side of blade 98 carry pivot pins 108 which pivotally couple one end of a link 1 10 to the blade. A second link 112 is pivotally connected as by pivot pin 114 to the opposite end of each link 110. The two links 112 are rigidly fixed to and interconnected by a hollow sleeve 116 which is in turn telescoped over cross frame member 56 of the pan assembly so that links 112 are pivotally supported upon the fixed frame of the pan assembly for pivotal movement about an axis established by cross frame member 56. A pair of hydraulic motors 118 have their cylinders pivotally mounted upon cross frame member 58 while the piston rods 122 of motors 118 are respectively pivotally coupled to the links 112 by pivot pins supported in bores 124 in links 112.

Referring now to FIGS. 1 and 2, in FIG. 1 blade 98 is shown in its fully retracted position in which the piston rods of motors 118 are retracted into their respective cylinders. In FIG. 2, blade 98 is shown in its forward most position in which piston rods 122 ofmotors 18 are fully extended from their respective cylinders.

From a comparison of FIGS. 1 and 2, it will be noted that when blade 98 is in its retracted position, gate 66 if in its retracted position forms an upwardly and forwardly curved extension of the snow engaging or forward surface of blade 98.

Referring now to FIGS. 5, 8, and 9 one exemplary form of hitch 22 is shown in FIG. 5. The actual construction of the hitch element is primarily determined by the particular type of towing vehicle employed, that shown in FIG. 5 being conformed for use with a Tucker Sno Cat in which the actual point of connection to the towing vehicle is on the rear deck indicated in broken line at 130. Hitch 22 in FIG. 5 is shown detached from main frame 20 of the snow handling apparatus, the attachment to main frame 20 being made by bolting a pair of rearwardly projecting arms 132 to the forward ends of frame members 24. Arms 132 are interconnected by a cross frame member 134, best seen in FIG. 3 and a rigid goose neck 136 is fixedly secured to the central portion of cross frame member 134 to project upwardly and forwardly from member 134. The horizontal upper arm portion 138 of goose neck 136 is laterally braced by a pair of struts 140 and a rigid stiffening web assembly 142 is welded on the inner corner of the gooseneck to further rigidify this structure.

A vertically disposed telescopic post assembly 144 is fixedly mounted at the forward end of member 138 of the gooseneck and projects downwardly to serve as the coupling element to the towing vehicle. Post assembly 144 consists of an outer sleeve 146 rigidly secured to member 138 and further braced by a web 148. A solid post 150 is slidably received within sleeve 146 and can be located at selected positions of telescopic adjustment relative to sleeve 146 by aligning a selected one of axially spaced bores 152 through posts 150 with a bore near the lower end of sleeve 146 and passing a pin 152 through the aligned bores.

A ball member 154 is fixedly secured to the lower end of post 150 and is held in position in a hitch coupling designated generally 156 which in turn is fixedly mounted upon the rear deck 130 of the towing vehicle. Referring to FIGS. 8 and 9, coupling 156 includes a rigid plate 158 fixedly mounted upon deck 130 at a space location above the surface of the deck. A bore 160 passes through plate 158, bore 161) being of a diameter slightly greater than that of ball 154. A pair of retainer arms 162 are mounted on the under side of plate 158 for pivotal movement about pivots 164. On the inner side edge of each of arms 162, a projecting ball retaining lug 166 is formed. Arm 162 can be spread so that lugs 166 are moved clear of the opposite sides of bore 160 to permit the ball 154 to pass downwardly through bore 160 until the ball rests upon a seat 168 fixedly mounted upon the bed 131). With ball 154 resting on seat 168, the two arms 162 are then swung to the position shown in FIG. 8 where lugs 166 overlie ball 154 to retain the ball against withdrawal upwardly 7 through bore 160. Clamping bolts 170, which are carried on arms 162 and pass through elongate slots 172 in plate 158, may be tightened to clamp the retaining arms 162 in their closed position.

The particular configuration of hitch 22 shown in FIG. 5 is required in that the roughness of the terrain in which the present apparatus is used is such that the hitch must not only be capable of pivoting about a vertical axis relative to the towing vehicle, but also about horizontal axes extending both fore and aft and transversely of the direction of movement of the assembly. In order to afford clearance during turns of the twoing vehicle of tight radius, the hitch must provide for adequate clearance from all portions of the towing vehicle, even in the event that sharp turns are made on steep hillsides.

In FIG. there is disclosed a schematic diagram of a typical hydraulic control system for the apparatus. Motors 34, 92 and 118 are shown only as single motors in the diagram of FIG. 10, however, it should be borne in mind that actually a pair of each of these motors are used, the motors of the respective pairs being connected in parallel to actuate in the same direction at the same time.

Most towing vehicles with which the apparatus of the present invention is employed are provided with a closed circuit hydraulic pumping system, schematically I illustrated at 176, Towing vehicles of this type conventionally include as part of the hydraulic pressure system two sets of outlets and two control valves for controlling hydraulically operated auxiliary equipment. The control valves are illustrated at 178 and are of conventional commercially available construction which are operable to provide variable speed control of movement in either direction of the piston rod ofa hydraulic motor coupled to the control. In the diagram of FIG. 10, one of the two control valves 178 is connected via lines 180 and 182 to control the motors 134- which are employed to raise or lower pan assembly 30 about the axis of roller 2%.

Because of their function and method of operation, gate assembly 66 and pusher blade assembly 68 are not required to operate simultaneously, thus affording the possibility of controlling these two elements from a single control member. To accomplish this, a pair of sequence valves 184 are employed in the hydraulic control circuit to effectively shift the connections of control valves 178a to either of motors 92 or 118. Se-

quence valves 184 are of a conventional and well known type of construction and are commercially available from several sources, such as Sta-Right Industries, Fluid Power Division of Racine, Wisconsin. It will be noted that the two valves 184 are of identical construction and each have two ports which are identified in FIG. 10 as the x port and y port. The x port of one sequence valve 184 is connected to the head end of motor 118, while the y port of the other sequence valve 184 is connected to the rod end of motor 92. The two remaining x and y ports are connected to each other via a common conduit 191) which is in turn connected via conduit 192 to the other control port of control valve 178a. Sequence valves'184 are constructed so that theycan be closed either by an abnormal increase in pressure at their x port or alternatively by an abnormal reduction in pressure at their y port. The valve can be opened by an abnormal increase in pressure at their y port or closed by an abnormal reduction in pressure at their 1: port.

The rod end of motor 19 and head end of motor 92 are connected in parallel by a conduit 186 which is in turn connected via conduit 188 to one of the control ports of control valve 178a;

The system is set up to operate as follows. For reasons to be described below in connection with the actual operation of the apparatus in snow handling, it is desired that movement of pusher blade 98 occur only when the gate assembly 66 is in its open or FIG. 2 position and that movement of gate assembly 66 occur only when pusher blade 98 is in its retracted or FIG. 1 position. To explain the operation of the sequence valves 184, it will be assumed that as an initial condition pusher blade 98 is in its fully retracted position, that gate 66 is in its fully open position in which the surfaces of the blade 98 and gate member effectively merge along a horizontal line joining the upper rear corners of pan assembly side panels 64. At this time, it will be assumed that the control lever of control valve 178a is in its neutral position, thus blocking any communication between supply and return lines 194 and 196 and the two control lines 192 and 188 at the opposite side of control valve 178a. Let it now be assumed that the lever of control valve 178a is pushed forward that is to the right as viewed in FIG. 10, from its neutral position and that movement of the control lever in this direction establishes a connection berween high pressure line 194 and control conduit 192 while at the same time connecting control conduit 188 to the low pressure return line 196 of the hydraulic system. It is apparent that by connecting control conduit 188 to low pressure or sump, the head end of motor 92 and the rod end of motor 118 are connected to the low pressure return side of the system. Neglecting the pressure side of the system for the moment, it will be seen that these connections would tend to cause the piston rod of motor 92 to be retracted and at the same time tend to cause the piston rod of motor 118 to be extended. However, at the instant of actuation of the control valve lever in this manner, gate assembly 66 was in its fully opened position and motor 92 thus had its piston rod fully retracted. Hence, pressure applied from conduit 192 through the lower most sequence valve 184 to the rod end of motor 92 cannot move the piston rod and pressure in this system builds up. In the'faceof this condition, sequence valve 184 closes and all of the pressure developed in conduit 192 is transmitted via the upper most sequence valve 184 to the head end of motor 118, causing this motor stroke to drive its piston rod outwardly, thus driving blade 98 forwardly. The closing of the lower most sequence valve 184 in effect traps a charge of hydraulic fluid at high pressure within conduit 200 which is connected between the y port of the lower sequence valve and the rod end of piston 92. With the control lever in its forward position, blade 98 will move forwardly until it either arrives at its forward limit of travel or it is deliberately stopped somewhere in between by returning the control lever of valve 178a to its neutral or blocking position.

To retract blade 98, the control lever of valve 178a is moved rearwardly or to the left from its neutral position as viewed in FIG. 10. This reverses the connection between the high and low pressure conduits and the control conduits to connect conduit 188 to the high pressure conduit 194 while connecting control conduit 192 to low pressure conduit 196. Referring to conduit 188, this conduit is now connected to the high pressure side of the pump and will supply pressure to the head end of motor 92. However, this pressure is opposed by the high pressure previously trapped in conduit 200 and thus thepump pressure is diverted to conduit 186 and the rod end of motor 118 whose head end is connected to the low pressure side of the system via the in conduit 200. This increase in pressure in conduit 200 eventually overcomes the closing bias of the lower sequence valve 184 and this lower valve now opens to permit venting of the rod end of motor 92 and consequently movement of gate 68 forwardly from its open position toward its closed position. At the same time, the reduction in pressure at the Y port of the upper most valve 184, caused by a suction in line 192 which can no longer withdraw fluid from the head end of motor 118 because the piston rod is fully retracted, causes the upper most sequence valve 184 to close.

Referring now to the apparatus in general, it may be operated selectively to remove or to transport or to plane snow as required. When used simply as a grader or planer, gate 66 is located in its fully opened position and pusher blade 98 is located in its extreme forward limit of movement. In this condition, the apparatus acts effectively as a scraper blade, the elevation of which is determined by raising or lowering the pan assembly by operation of motors 34.

When employed to remove or to transport snow, the gate is located in its open position and pusher blade 98 is moved to its fully retracted position. The apparatus is then towed acoss the area from which the snow is to be removed with the forward end of the pan assembly lowered to scope up snow at the desired depth. Snow is collected in the interior of the pan assembly on top of bottom panel 60, between pan assembly side plates 64 and forwardly of the retracted blade 98 which, in this situation, effectively acts as the rear wall of the pan. By locating gate 66 to form an effective upward and forward continuation of the forward surface of plate 98, the tendancy of the collected snow to wash over the upper edge of blade 98 is eliminated because the inner surface of gate 66 causes this snow to be pushed upwardly and forwardly and to fall back down into the pan rather than flowing rearwardly over the upper edge of the blade. This causes the entire interior of the pan to be filled with snow, and when filing is accomplished the gate is shifted to its closed position by actuation of motors 92. The curved configuration of gate 66 in which its main panel 72 is concentric with the axis of pivotal movement of the gate enables the gate to act as a blade during this closing movement to pass smoothly and easily through the collected snow until the gate is in its fully closed position.

At this time, all of the snow is captured in the pan assembly and is retained in the assembly even though the apparatus may travel down step grades while moving to the location at which the snow is to be dumped. Upon arriving at the location at which the snow is to be dumped, the gate is moved to its open position while the apparatus is towed at the desired speed across the area of dumping. As the aparatus moves forwardly, pusher blade 98 is moved forwardly from its retracted position at a controlled rate to push the collected snow forwardly from the pan assembly through the now open forward end of the apparatus. The freshly deposited snow will become packed by the trailing roller 28.

While one embodiment of the invention has been described in detail, it will be apparent to those skilled in the art that the disclosed embodiment may be modified. Therefore, the foregoing description is to be considered exemplary rather than limiting, and the true scope of the invention is that defined in the following claims.

I claim:

1. Snow handling apparatus comprising frame means adapted to be towed by a towing vehicle, a pan assembly mounted upon said frame means having a flat rectangular bottom panel, a pair of spaced parallel side wall panels fixedly secured to and projecting upwardly from the opposed side edges of said bottom panel, a pusher blade extending transversely between said side wall panels, roller means mounting said pusher blade upon said bottom panel for forward and rearward movement, first power means for driving said pusher blade in movement between a normal position adjacent to the rearward edge of said bottom panel whereat said pusher blade defines the rearward wall of a snow carrying chamber and a forward position adjacent to the front edge of said bottom panel, a gate having a width substantially equal to the spacing between said side wall panels, means mounting said gate on said side wall panels for pivotal movement about a horizontal axis parallel to the front edge of said bottom panel, and a second power means for driving said gate in pivotal movement between an open position wherein said gate constitutes a vertical extension of said pusher blade when said pusher blade is in said normal position and a closed position wherein said gate extends between said side wall panels adjacent to the front edge of said bottom panel.

2. Apparatus as defined in claim 1 wherein said pan assembly comprises a first cross frame member extending transversely of said assembly between locations adjacent to the upper rear corners of said side wall panels, a second cross frame member on said pan assembly extending transversely across said assembly at a location spaced rearwardly and upwardly from said first cross frame member, said first power means comprising a first link mounted for pivotal movement about the axis of said first cross frame member, a second link pivotally connected at one end to one end of said first link and pivotally coupled at its opposite end to the rearward side of said blade, and hydraulic motor means interconnected between said second frame member and said first link.

3. Apparatus as defined in claim 1 in which said gate means includes a gate member of sheet material curved concentrically of said horizontal axis and the pivotal movement of said gate is in an arc coincident with the curvature of said gate member.

4. Apparatus as defined in claim 1 in which said pusher blade has a curvature, generally around a horizontal axis extending through said side wall panels forwardly of the rear edge of said bottom panel and parallel to the front edge of said bottom panel, to deflect upwardly snow pressed rearwardly relative to said pusher blade.

. 5. Apparatus as defined in claim 4 in which said first power means is coupled to said pusher blade only along the lower and forward portion of said pusher blade in order to exert force primarily at'the bottom of said pusher blade. I

6. Snow handling apparatus comprising:

an open frame assembly;

a snow compacting roller mounted in said frame assembly for rotation about a horizontal axis extending transversely across the rearward end of said frame assembly;

hitch means on the forward end of said frame assembly for coupling said frame assembly to a towing vehicle;

a pan assembly having a flat rectangular bottom panel and spaced vertical side panels fixed to and extending upwardly from opposite side edges of said bottom panel;

means mounting the rearward end of said pan assembly on said frame assembly for pivotal movement about an axis extending transversely across the rearward end portion of said frame assembly;

first power means coupled between said frame assembly and the forward end of said pan assembly for raising and lowering the forward end of said pan assembly about said axis of said pivotal movement;

blade means mounted on said pan assembly for reciprocation between said side panels between a retracted position adjacent to the rearward end of cent to the front edge of said bottom panel;

gate means mounted on said pan assembly for pivotal movement about an axis, parallel to said axis of said roller and located above said bottom panel between the front and rear edges of said side panels, between a closed position wherein said gate means is located adjacent to the front edge of said bottom panel and extends between the forward edges of said side panels to close the front end of said pan assembly and an open position wherein said gate means is located above the rearward ends of said side panels, said gate means including a gate member of sheet material curved concentrically of said axis of pivotal movement of said gate means and defining an upward extension of said blade means when said gate means is in its open position and said blade means is in its retracted position;

and second power means for shifting said gate means between said open and closed position when said blade means is in said retracted position and for shifting said blade means between said retracted and said extended position when said gate means is in said open position.

7. Snow handling apparatus comprising a pan assembly having a flat rectangular bottom panel and a pair of vertical side panels fixedly secured to and extending upwardly from opposite sides of said bottom panel, hitch means at the forward end of said pan assembly for coupling said pan assembly to a towing vehicle, a roller rotatably mounted at the rearward end of said pan assembly for supporting said assembly for trailing movement behind said towing vehicle, first power means for raising and lowering the forward end of said pan assembly relative to said roller, a pusher blade mounted for movement between said side panels from a retracted position at the rearward end of said bottom panel to an extendence position at the forward end of said bottom panel, said blade when in said retracted position defining the rearward end of a snow carrying chamber having sides and a bottom constituted by said side and bottom panels, and gate means movable when said blade is in a retracted position between a closed position wherein said gate means defines the front end of said snow carrying chamber and an open position wherein said gate means defines an upward extension of said rearward end of said chamber, and second power means operable when said gate means is in said open position for driving said blade between said retracted and said extended position.

8. The invention defined in claim 7 wherein said gate means is mounted for pivotal movement about a horizontal pivot axis parallel to the axis of rotation of said roller and extending transversely through said side panels, said gate means including a transversely extending gate member curved in concentrically to said pivot axis.

9. The invention defined in claim 8 wherein said power means is operable when said gate is in said open position to shift said blade between said extended and said retracted position. I 

1. Snow handling apparatus comprising frame means adapted to be towed by a towing vehicle, a pan assembly mounted upon said frame means having a flat rectangular bottom panel, a pair of spaced parallel side wall panels fixedly secured to and projecting upwardly from the opposed side edges of said bottom panel, a pusher blade extending transversely between said side wall panels, roller means mounting said pusher blade upon said bottom panel for forward and rearward movement, first power means for driving said pusher blade in movement between a normal position adjacent to the rearward edge of said bottom panel whereat said pusher blade defines the rearward wall of a snow carrying chamber and a forward position adjacent to the front edge of said bottom panel, a gate having a width substantially equal to the spacing between said side wall panels, means mounting said gate on said side wall panels for pivotal movement about a horizontal axis parallel to the front edge of said bottom panel, and a second power means for driving said gate in pivotal movement between an open position wherein said gate constitutes a vertical extension of said pusher blade when said pusher blade is in said normal position and a closed position wherein said gate extends between said side wall panels adjacent to the front edge of said bottom panel.
 2. Apparatus as defined in claim 1 wherein said pan assembly comprises a first cross frame member extending transversely of said assembly between locations adjacent to the upper rear corners of said side wall panels, a second cross frame member on said pan assembly extending transversely across said assembly at a location spaced rearwardly and upwardly from said first cross frame member, said first power means comprising a first link mounted for pivotal movement about the axis of said first cross frame member, a second link pivotally connected at one end to one end of said first link and pivotally coupled at its opposite end to the rearward side of said blade, and hydraulic motor means interconnected between said second frame member and said first link.
 3. Apparatus as defined in claim 1 in which said gate means includes a gate member of sheet material curved concentrically of said horizontal axis and the pivotal movement of said gate is in an arc coincident with the curvature of said gate member.
 4. Apparatus as defined in claim 1 in which said pusheR blade has a curvature, generally around a horizontal axis extending through said side wall panels forwardly of the rear edge of said bottom panel and parallel to the front edge of said bottom panel, to deflect upwardly snow pressed rearwardly relative to said pusher blade.
 5. Apparatus as defined in claim 4 in which said first power means is coupled to said pusher blade only along the lower and forward portion of said pusher blade in order to exert force primarily at the bottom of said pusher blade.
 6. Snow handling apparatus comprising: an open frame assembly; a snow compacting roller mounted in said frame assembly for rotation about a horizontal axis extending transversely across the rearward end of said frame assembly; hitch means on the forward end of said frame assembly for coupling said frame assembly to a towing vehicle; a pan assembly having a flat rectangular bottom panel and spaced vertical side panels fixed to and extending upwardly from opposite side edges of said bottom panel; means mounting the rearward end of said pan assembly on said frame assembly for pivotal movement about an axis extending transversely across the rearward end portion of said frame assembly; first power means coupled between said frame assembly and the forward end of said pan assembly for raising and lowering the forward end of said pan assembly about said axis of said pivotal movement; blade means mounted on said pan assembly for reciprocation between said side panels between a retracted position adjacent to the rearward end of said bottom panel and an extended position adjacent to the front edge of said bottom panel; gate means mounted on said pan assembly for pivotal movement about an axis, parallel to said axis of said roller and located above said bottom panel between the front and rear edges of said side panels, between a closed position wherein said gate means is located adjacent to the front edge of said bottom panel and extends between the forward edges of said side panels to close the front end of said pan assembly and an open position wherein said gate means is located above the rearward ends of said side panels, said gate means including a gate member of sheet material curved concentrically of said axis of pivotal movement of said gate means and defining an upward extension of said blade means when said gate means is in its open position and said blade means is in its retracted position; and second power means for shifting said gate means between said open and closed position when said blade means is in said retracted position and for shifting said blade means between said retracted and said extended position when said gate means is in said open position.
 7. Snow handling apparatus comprising a pan assembly having a flat rectangular bottom panel and a pair of vertical side panels fixedly secured to and extending upwardly from opposite sides of said bottom panel, hitch means at the forward end of said pan assembly for coupling said pan assembly to a towing vehicle, a roller rotatably mounted at the rearward end of said pan assembly for supporting said assembly for trailing movement behind said towing vehicle, first power means for raising and lowering the forward end of said pan assembly relative to said roller, a pusher blade mounted for movement between said side panels from a retracted position at the rearward end of said bottom panel to an extendence position at the forward end of said bottom panel, said blade when in said retracted position defining the rearward end of a snow carrying chamber having sides and a bottom constituted by said side and bottom panels, and gate means movable when said blade is in a retracted position between a closed position wherein said gate means defines the front end of said snow carrying chamber and an open position wherein said gate means defines an upward extension of said rearward end of said chamber, and second power means operable when said gate means is in said open position fOr driving said blade between said retracted and said extended position.
 8. The invention defined in claim 7 wherein said gate means is mounted for pivotal movement about a horizontal pivot axis parallel to the axis of rotation of said roller and extending transversely through said side panels, said gate means including a transversely extending gate member curved in concentrically to said pivot axis.
 9. The invention defined in claim 8 wherein said power means is operable when said gate is in said open position to shift said blade between said extended and said retracted position. 